Oldest fossilized forest
Cairo New York fossilized forest
386,000,000 year(s)
United States (Cairo)

Fossilized tree roots discovered in 2009 at a quarry between the Catskill Mountains and the Hudson River – located near Cairo, New York, USA – have been dated circa 386 million years old, placing them in the mid Devonian epoch. The period from which the tree remains date represents a transition phase in Earth’s history when forests became prevalent across the planet – some 150 million years before the first dinosaurs would emerge. The findings were published in the journal Current Biology on 19 December 2019.

The Cairo forest predates the next oldest forest – also located in New York State, at nearby Gilboa – by 2 to 3 million years. At Gilboa, not only are roots preserved, but also the bases of some tree trunks are cast in sandstone.

The Cairo forest comprised at least three types of tree: Cladoxylopsids, Archaeopteris and a third kind that has yet to be identified. Some of the largest Archaeopteris trees found on the site had roots that were 15 cm (6 in) in diameter and that fanned out up to 11 m (36 ft) from where the trunks once stood.

The presence of fossilized fish in the quarry indicates that the forest may have been wiped out by flooding.

The study was a collaboration between Binghamton University, New York State Museum (both USA), Cardiff University, the University of Sheffield and the University of Southampton (all UK), led by Emeritus Professor William Stein, Dr Christopher Berry and post-doc Jennifer Morris.